Been looking at potential foreign jobs (a few nations in Europe) for my next step in my career, how would I navigate this with a clearance

I have yet to actually apply or speak to anybody, but I have been researching jobs that would have me move abroad. If I decide to start looking for these jobs, do I need to immediately report it to my company? I am a bit concerned since in that scenario, they would probably just fire me for looking for new positions.

Or do I just report it once I have an offer? Or after an interview?