Installation and https activation

i have installed UCS over OVA, everything has worked perfectly just one issue is there and
can’t be solved after weeks of searching :frowning:
My issue is after installing LetsEncrypt Certifcate i can’t open nextcloud, i just get a error, site is not
secure but installation of certificate over LetsEncrypt has worked.
I will be very thank full if someone from communit can help me to solve my problem.
Thanks in advace