Was able to get the solution after some frustration late on a Friday 🙂 Main problem was us creating too many connections by accident since we were putting in the incorrect API key/ key secret and even if we got the correct ones after we passed the limit of two - hence the "maximum number of connections" message.
First solve in Power Automae: Remove connections in Power Automate by going to the main make.powerautomate.com left-hand menu > data > connections > click the three dots "ellipsis" next to the failed twitter connections > delete
Second solve in Twitter Developer: Start fresh by going to your dashboard and click the gear icon > click "Edit" > Delete App (save your app name for when you re-create)
Create a new app by clicking "Add App" > name it your saved name (a new name wouldn't work for me) > copy your API Key and Key Secret (these are the correct API keys you will need).
Lastly set up the user authentication settings: Click "Read and write and Direct message" > Click "Web Apps, Automated App or Bot" > put in https://global.consent.azure-apim.net/redirect for the "Callback URI/ URL" and "Website URL" > Click "Yes" when changing permissions.
^the above link took me a while to find within the documentation.
Once you've done all of the above, go back to your power automate twitter connection, put in your API Key and Key secret and the twitter login pop-up will successfully appear!
Cheers! Was happy to see I wasn't alone on this and that I can hopefully help others wanting to learn Power Automate. Really not sure why they are using 3rd party connectors like twitter and mailchimp for these exercises.
