Exporting list of Team members without coding

If you have admin permissions, you can export the list via the Teams admin center, or PowerShell. If not, it's a bit more complicated. There are some workarounds via Outlook, but those require the Team to be "visible" therein, which doesn't seem to be the case. Instead, consider using a Flow, such as the one here: https://emea.flow.microsoft.com/en-us/galleries/public/templates/2cc5e634806746aba3d303c3e905001c/get-a-weekly-email-with-the-members-of-all-my-office-365-groups/

Or you can open the Team Members page, select all text via CTRL+A, then copy/paste. It will require some cleanup, but at least it doesn't involve using any other tools 🙂