Is the rubber part arround the nozel important?

Hi again,
this link will be shown when your mouse pointer hovers over the blue text & will be opened when you click the blue text…
This is the above link again:

& again in plain text: https://www.youtube.com/watch?v=Lx5ndVX-l6k

It can be found here, too:

It is the third video named " How to clean hotend clean nozzle | Sovol SV04" - the assembly part will be shown beginning from minute 1:57.

Good luck!
Björn