We had to get into the venue. , that was impossible, since we didn't have tickets. Which transition word or phrase would be most fitting to use here?

The transition word that is most fitting is - However.

Explanation:

However is a transition word that introduces a statement which is surprising or is in contrast to what has been previously said. In the context of this question, However is the most fitting transition word to use because it can start a sentence as against the word - But which is a close alternative.

first, you have to go to settings, click on your profile, go to profile settings, and you'll find the setting there.