I ordered a 28-ounce seam filler tube without a nozzle. It needs to be Creality Ender Mother.

Simple design. The thread size is 7/8 inch with 14 threads per inch. All other parameters are arbitrary. No support is required for the current shape. I read in the design notes that someone printed a nozzle for standard-sized seal guns, using ABS or PETG to enhance strength. I haven’t tested PETG, but ABS worked well.