Authentication ACS <-> CPE v1.2

I haven’t yet found how to authenticate both ways (ACS -> CPE and CPE -> ACS) in v1.2 of GenieACS. And it doesn’t help that http://docs.genieacs.com/en/latest/cpe-authentication.html isn’t written.

In the release at GitHub, it is stated that

“the connection request authentication behavior can now be customized using an ‘expression’.”

Which expression?

Thank you

See my answer here: Incorrect connection request credentials (v1.2)

Hi @zaidka thanks for your help.

Before using the configuration with the authentication method that you propose, I got the following error:
Connection request error: Incorrect connection request credentials

After implementing the authentication method that you propose, I get the following error:
No contact from CPE

It seems that the authentication works, but for some reason the parameters are not being obtained from the CPE

my cpe, they have the following configuration for TR69
link with all screenshots : geniacs — ImgBB

I appreciate any support you can give me