The plain HTTP request was sent to HTTPS port

i have a docker container and added a rule to one of my domains. on port 80 the docker containers works very well. But when i change the proxy rules to port 443 (docker internal) i getting 400 Bad Request The plain HTTP request was sent to HTTPS port - error. what can i do?

Systems is Ubuntu 22 with Plesk 18

Please provide more details that actualy allow to understand your specific setup.

I have installed passbolt in a docker container. everything looks good with port 80. But when i want top open it under https (port 443) . iam getting this error. I think it is an nginx missconfiguration.

CPU AMD EPYC 7282 16-Core Processor (10 core(s))
Version Plesk Obsidian v18.0.44_build1800220614.11 os_Ubuntu 22.04
OS Ubuntu 22.04 LTS

I was more refering about how you run the involved containers…