The issue is that (due to new battery transit label requirements in the last few years?) very few of the ecommerce retailers will ship power banks to the whole island of Ireland. The selection from local retailers/websites is poor and over-priced. Quite frustrating.
Otterbox will ship but I doubt any of them are sufficient for OP's need, which is probably for 45W or 65W USB PD, minimum.
Aliexpress claim to ship, but I'm not convinced the package won't be blocked at some point, and it's hard to be sure what you're getting.