There are different ways for finding installed certificates in cert store and one of them is by using thumbprint:
using X509Store store = new(StoreLocation.CurrentUser);
store.Open(OpenFlags.ReadOnly);
X509Certificate2Collection certCollection = store.Certificates;
using X509Certificate2 cert = certCollection.Find(X509FindType.FindByThumbprint, "139FAA424C85CDCA61E0EB63895B0B3AA395471E", validOnly: true).First();
But I'm trying to find an easier way for the client to find their certificate like using the file's name or sth more reachable than thumbprint. By the way, I don't want them to specify file path and password because they should use an installed certificate hence should look for it in the cert store.