Impossible to install pysnmp?

Hi guys
I would like to install pysnmp package, but it couldn’t because python3.9 is already installed in Vyos
pysnmp need a python version 3.5
Is there any way to install it??

[Error message]

The following packages have unmet dependencies:
python3-crypto : Depends: python3 (< 3.6) but 3.9.2-3 is to be installed
E: Unable to correct problems, you have held broken packages.