How to Simulate Ag+ Ions in a gromos54a7 ff

GROMACS version: 23.2
GROMACS modification: Yes/No

I’m using the gromos54a7 forcefield. How can I simulate Ag+ ions when the ions.itp file built in the forcefield folder does not have parameters for Ag+ ions?

By any chance, is there any site or paper where I can get the parameter file for the Ag+ ion?