Unless there’s a very specific reason (for example, in some baking recipes), using salted or unsalted butter is up to you. 99% of recipes require adding some salt to enhance flavor either way. Don’t overthink salted/unsalted. Use what you have and taste before serving. Tasting is more important than which butter you use. Tasting is when you are in control of the outcome of your dish. Regularly taste throughout preparing your meals. Make it a habit and your end results will improve dramatically.