Hi Giuseppe,
Automate supports .pem certificate files which from what I could gather is what is used for mTLS.
Privacy Enhanced Mail Certificate (.pem) - Base64-encoded certificate file, such as a PEM-encoded X509 certificate; used to authenticate a secure website; typically imported from a Unix-based Apache Web server and compatible with OpenSSL applications. PEM certificate files are generated automatically and are not meant to be opened or edited manually.