Scientists tell us antimatter is too expensive to be used for spacecraft fuel. A device could be built based on the AMS experiment on the ISS where antimatter gets directed to count but instead add onto the design to incorporate natural particle accelerators in space and add components to create antimatter instead of needing to use enormous amounts of energy to speed particles up to make antimatter. I'm not a scientist, I have had an interest in space since I was young and read some advanced books when I was 19, but I do know the energy required to speed particles up to make antimatter on Earth, takes a lot of energy which is very expensive. Conditions in space are ideal for creating antimatter away from Earth at a much cheaper cost.
Storage is the issue, I believe within 10 years new solutions can be developed with the proper investment, or others may come up with a new design before 10 years. A design from the 1990s was able to store some, surely we can figure this out even maybe by the time things are functional on the Moon to have faster and safer trips to Mars and beyond. The investment right now is just not there, or if it is, it's something at some place like Area 51 and sometime in the future it will be made public like the stealth aircraft were kept secret. God knows if it's possible to one day tap into the antimatter coming from black holes, a massive storm in space that is very dense. If black holes magnetic fields can flip, then there might be a period of time where some light tries to escape the black hole revealing details, we can't know from here, we need to get a space telescope out in deep space as close to the black hole to know, diffraction and different effects related to gravitational lensing may offer a different view here than upfront because were not seeing all the detail so far away, and photographing something in a long exposure doesn't get the detail as recording 30 frames per second or 120.