I bought a bottle of "RoXolid Wood X" wood glue at the Hornbach. Unfortunately, the cap broke off with the first use, it's tiny and white and I've already spent a lot of time trying to find it, so I printed a replacement that is larger and red.

I made it to fit this specific bottle, but it will probably fit others too, it is 8mm wide at the top and 10.8mm at the bottom, with a little extra width to make it easier to put on. The OpenSCAD model is included, so you can make your own adjustments.