Encrypt url parameter from external site

An external site, not made in Wappler, is linking to my site and we wish to add a simple encryption to a url parameter.
Encrypt / Decrypt with password would be a good choice I think.

But how do the other site implement the encryption so that it works with Wappler’s Decryption.

Does anyone have a ASP.NET C# snippet for the encryption.

Hope someone can help

Olav