I couldn't find a power bank that met my needs so I designed this one. It has a little more room inside as I wanted to make use of some old 18650 cells I had that came from a stairlift and had paper wrappings so were mote like 19mm diameter.

I also had some of these little USB C charge circuits from AliExpress that I wanted to use, they are cheap and good enough for my needs

https://www.aliexpress.us/item/3256806958476985.html

You will also need a 6x6mm push switch. I went for the 8mm height switch but anything longer than 7mm should be ok, if you go smaller than 7mm you will probably need a tool to press the switch. (switch is connected between K and the -5V

https://www.aliexpress.us/item/3256805183101234.html

And a couple of screws, I used M3x12mm, the holes are 2.5mm in the body but I drill and tap them for the M3 screws, alternatively self tapping screws should work.

The base and separator print without support but the top will need supports. The separator isn't necessarily needed, I just used kapton tape on the first one I made and it seems ok.

I printed in PLA with 0.2mm layers but it should be ok in most non flexible materials

you will need to use a dab of glue to fix the switch and circuit in place, I used hot glue.

I take no responsibility for anything that happens making or using this, please use your own judgement and if you are not confident with soldering, working with batteries or anything else please get someone suitable to help.
A word of caution, never solder directly onto lithium batteries, the heat will most likely cause damage and could cause them to explode.

My printer is a Sovol SV08 not 07 (08 is not in list)