I had been searching this as well, and as far as I've seen, no, you can't :(
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Go and talk to the owner of poketch in poketch company's building he will install the marking map app in your poketch
You cannot
yOU CAN NEVER EVER GET IT IN POKEMON BLACK(ONLY IF YOU ARE DREAMING)
It's on your Poketch.
the poketech company is in jubilife