Yes, it is often done this way.

Thank you Sir.

Just stick with references at the bottom of the poster will be okay.

Thank you Prof Badawy

Add the citation number in the body of the poster (1) to correspond with the reference list below (2).

Reference

1. Names. Year. Title, Volume(issue) pp. DOI or weblink to the source.

2. Names. Year. Title, Volume(issue) pp. DOI or weblink to the source.

Add ref in poster body as separate heading and you may not add in citation

You can use the Vancouver style of referencing. It will occupy less space.