The energy credit rules in place when the installation and purchase is made/placed in service would apply:
"Timing of the credits: costs are treated as being paid when the original installation of the item is completed, or, in the case of costs associated with the reconstruction of a taxpayer’s home, when his or her original use of the home begins."
Source: The Tax Book
The current tax rules for energy credit for 2022 can be found here:
Energy credit tax rules 2022
Windows would qualify for up to $200 of the total $500 lifetime energy credit allowed and would be reported on your 2022 tax return.