Cannot add SSL certificates to iPhone 14 Max Pro and 9th generation iPad

My scientific consulting business has two workspace email accounts, one with GoDaddy and one with Arvixe. These work fine under Outlook 365 under Win 10 and 11 PCs and under Gnome Evolution for Linux PCs. They do not work consistently on iPad, and the GoDaddy account will not work on iPhone. For example, when Outlook starts up, it asks me to trust the SSL certificates for both the GoDaddy and Arvixe email accounts. Gnome Evolution does not ask, it just works. How do I set up my iPad and iPhone so that they will work with my email accounts?

John