You don’t, sorry
Muse removed these for 3.2.1 (and onwards) as part of tidying up the GUI.
You have a few options:
-
Right-click in the waveform to get a context menu
-
use the Edit Menu: Edit>Cut etc.
-
use the shortcuts
Ctrl+C => Copy
Ctrl+K => Delete
Ctrl+V => Paste
Ctrl+X => Cut (actually cut and copy)
You are not the first person to complain about these missing buttons and I suspect that you will not be the last - but Muse are fairly adamant about not bringing them back, sorry.
See this thread: https://forum.audacityteam.org/t/audacity-3-2-0-please-bring-back-cut-copy-paste-buttons/65631/1
and there are other similar threads
And see this issue that I logged on GitHub but which Muse closed
Restore the Cut, Copy and Paste buttons as a new (hidden by default) toolbar #3693
https://github.com/audacity/audacity/issues/3693
Peter