1. leave smtp detail blank
2. PHP REQUIREMENT LINK : https://docs.opensupports.com/guides/installation/#server-requirements
3. Do manual installation on non SU-PHP server with https support as script dev has mentioned that, OpenSupports has issues with non-secure HTTP
https://github.com/opensupports/opensupports/issues/1067 (Since 4.10.0)
4. We have set Max PHP support to 7.2.x as suggested by vendor via email.