Hi,
Thanks for your query.
Please publish an offcanvas module on offcanvas position.
Here is how to do:
Please go to Extensions>modules
Then find out if there any module named offcanvas:
https://prnt.sc/pzghid
If there exists an offcanvas module then make sure it is published on offcanvas position:
https://prnt.sc/pzggkv
If there is no offcanvas module then create a new module:
https://prnt.sc/pzgi4s
and fill/set the desired options:
https://prnt.sc/pzggkv
Then save and close.
Hope this helps.
Best Regards