Come join a world-class team of designers who care about making the world a better place. Just submit your portfolio – that part is pretty important. Show us what you can do. Longer posting here: https://careers.mozilla.org/en-US/position/oCLY0fw5
Contact @cassiemc or email@example.com
Separate to that, we are only able to hire within the jurisdictions mentioned, so for your situation you would have to reside in the UK (by my understanding). If you were willing to relocate, great, please do apply!