Unfortunately there’s no copy bank function. You can copy and rename a bank in Ot’s file manager in order to replace another bank in another project, but it is easier with a computer writing on the card.
You also have to collect samples in each project you want to copy. Samples slots positions have to be the same. Make a list of samples you need.
You can arrange sample slots in former projects and copy banks if I remember well. Not sure.
I think I edited the project file with the new sample slot list, copying from old project.
To sum up, you need a good night and a lot of coffe, know what are file paths, use text editor…