Repository: microsoft/PowerToys
File: src/modules/poweraccent/PowerAccent.Core/Languages.cs (C#)

Code before:
                LetterKey.VK_U => new[] { "ü" },
                _ => Array.Empty<string>(),
            };
        }

        // Greek
        private static string[] GetDefaultLetterKeyEL(LetterKey letter)
        {
            return letter switch
            {
                LetterKey.VK_A => new string[] { "α" },
                LetterKey.VK_B => new string[] { "β" },
                LetterKey.VK_C => new string[] { "χ" },
                LetterKey.VK_D => new string[] { "δ" },
                LetterKey.VK_E => new string[] { "ε", "η" },
                LetterKey.VK_G => new string[] { "γ" },
                LetterKey.VK_I => new string[] { "ι" },
                LetterKey.VK_K => new string[] { "κ" },
                LetterKey.VK_L => new string[] { "λ" },
                LetterKey.VK_M => new string[] { "μ" },
                LetterKey.VK_N => new string[] { "ν" },
                LetterKey.VK_O => new string[] { "ο", "ω" },
                LetterKey.VK_P => new string[] { "π", "φ", "ψ" },
                LetterKey.VK_R => new string[] { "ρ" },
                LetterKey.VK_S => new string[] { "σ" },
                LetterKey.VK_T => new string[] { "τ" },
                LetterKey.VK_U => new string[] { "υ" },
                LetterKey.VK_X => new string[] { "ξ" },
                LetterKey.VK_Y => new string[] { "υ" },
                LetterKey.VK_Z => new string[] { "ζ" },
                _ => Array.Empty<string>(),
            };
        }

        // Hebrew
        private static string[] GetDefaultLetterKeyHE(LetterKey letter)
        {
            return letter switch
            {
                LetterKey.VK_A => new[] { "שׂ", "שׁ", "\u05b0" },
                LetterKey.VK_B => new[] { "׆" },
                LetterKey.VK_E => new[] { "\u05b8", "\u05b3", "\u05bb" },
                LetterKey.VK_G => new[] { "ױ" },
                LetterKey.VK_H => new[] { "ײ", "ײַ", "ׯ", "\u05b4" },
                LetterKey.VK_M => new[] { "\u05b5" },
                LetterKey.VK_P => new[] { "\u05b7", "\u05b2" },
                LetterKey.VK_S => new[] { "\u05bc" },
                LetterKey.VK_T => new[] { "ﭏ" },
                LetterKey.VK_U => new[] { "וֹ", "וּ", "װ", "\u05b9" },
                LetterKey.VK_X => new[] { "\u05b6", "\u05b1" },
                LetterKey.VK_Y => new[] { "ױ" },

Review comment (suggestion):
```suggestion
                LetterKey.VK_T => new string[] { "τ", "θ" },
```
I think you forgot to add θ (theta)

Code after:
        }

        // German
        private static string[] GetDefaultLetterKeyDE(LetterKey letter)
        {
            return letter switch
            {
                LetterKey.VK_A => new[] { "ä" },
                LetterKey.VK_E => new[] { "€" },
                LetterKey.VK_O => new[] { "ö" },
                LetterKey.VK_S => new[] { "ß" },
                LetterKey.VK_U => new[] { "ü" },
                _ => Array.Empty<string>(),
            };
        }

        // Greek
        private static string[] GetDefaultLetterKeyEL(LetterKey letter)
        {
            return letter switch
            {
                LetterKey.VK_A => new string[] { "α" },
                LetterKey.VK_B => new string[] { "β" },
                LetterKey.VK_C => new string[] { "χ" },
                LetterKey.VK_D => new string[] { "δ" },
                LetterKey.VK_E => new string[] { "ε", "η" },
                LetterKey.VK_F => new string[] { "φ" },
                LetterKey.VK_G => new string[] { "γ" },
                LetterKey.VK_I => new string[] { "ι" },
                LetterKey.VK_K => new string[] { "κ" },
                LetterKey.VK_L => new string[] { "λ" },
                LetterKey.VK_M => new string[] { "μ" },
                LetterKey.VK_N => new string[] { "ν" },
                LetterKey.VK_O => new string[] { "ο", "ω" },
                LetterKey.VK_P => new string[] { "π", "φ", "ψ" },
                LetterKey.VK_R => new string[] { "ρ" },
                LetterKey.VK_S => new string[] { "σ" },
                LetterKey.VK_T => new string[] { "τ", "θ" },
                LetterKey.VK_U => new string[] { "υ" },
                LetterKey.VK_X => new string[] { "ξ" },
                LetterKey.VK_Y => new string[] { "υ" },
                LetterKey.VK_Z => new string[] { "ζ" },
                _ => Array.Empty<string>(),
            };
        }

        // Hebrew
        private static string[] GetDefaultLetterKeyHE(LetterKey letter)
        {
            return letter switch
            {