Denemo icon missing in application menu

[Lib Lists]

Hello,
I compiled and installed (sudo make install) Denemo, and a Denemo
launcher in the application menu was created. However (see attached
screenshot) it doesn't display Denemo's icon.
Not a big issue, but it would be nicer to have Denemo's icon there, if possible.
I'm using Lubuntu 20.04 and the desktop environment is LXQt 0.14.1
I'm not really familiar with Linux (I'm using it only with Denemo) so
apologies for the possibly trivial question.
Thank you,
Lib