I liked the lids from https://makerworld.com/en/models/165093#profileId-181392 very much, but I wanted the tube to stay in Place and not slide into the box all the time.

So I made a lid, with a M6 thread, so you can screaw PC4-M6 Straight Fittings into the lid. To make this possible I had to make other ajustments.

You can buy these fittings on amazone:

https://amzn.eu/d/0DQyGTL