Cannt install letsencrypt for Debian 8

Thank you. I did a lot of changes and i am in another step. I pu my email address,alll looks like certificate is generating, but then get error

The client lacks sufficient authorization :: Account creation on ACMEv1 is disabled. Please upgrade your ACME client to a version that supports ACMEv2 / RFC 8555. See End of Life Plan for ACMEv1 for details.

I am not sure what should i update/install