Do you mean "excess contributions"? If so, if you do not withdraw the excess contributions before April 15, 2025, then they will be carried over to 2025 as a personal contribution (you will be hit with a 6% excise tax on the carryover).
There is no such thing as "excess funds in an HSA". An HSA can contain as much money as you put in it (and what it can earn), and this fund persists from year to year. In this sense, it is not dissimilar to an IRA. An HSA is very different from an FSA where any money not used by the end of the year is lost.
Is this what you meant?