How to change your ablities at end of round?

[Citrus]

It says right ability to change but it doesn't do anything for me while I sit there looking at someone else seemingly changing theirs.

[Enginseer]

Bottom right, click on the arrow then use left/right or click on the side arrows to change

[Citrus]

Sweet, that was not obvious to me, thank you

[TheZipBon]

You can also press W (or whichever key you use to move your slime up).