This is a useful but difficult-to-remember command for PSQL:

\pset pager off

Or, if the invocation of psql is within control, add the -P pager=off argument:

psql -P pager=off ...

This turns off a “more” type of feature when displaying long results to allow paging up and down the results.

Unlike when using text-base terminals, most terminals nowadays are in a GUI shell with scroll buffers. We can scroll back and forward just fine, thank you very much.