Insert Telekom email address in Gmail on the laptop?

Can I call up and send my Telekom email address on my laptop via Google Mail (Gmail)? So not via the app. If so. How?

Windows Mail can be used on the laptop for all existing e-mail addresses.

Here is a guide on how to link your mail account to Google. https://support.google.com/...roid&hl=de

You should then be able to log in to Gmail with your Telekom email address, possibly you could also have your emails forwarded to a Gmail address & label it with Gmail.