Yes, you can carry forward any unused FHSA contribution room from the prior year up to a maximum of $8,000 (subject to your lifetime contribution limit of $40,000). This means that if you contribute less than $8,000 within the year, you can contribute the unused amount in the subsequent year in addition to the $8,000 annual contribution limit.
For example, if you contribute $5,000 to your FHSA in 2023, you would be allowed to contribute $11,000 in 2024 (i.e., $8,000 plus the remaining $3,000 from 2023).