You used to be able to on OW1, they removed that feauture June 2021, despite still being able to select your region for OW1 on the bnet launcher, it will still force you into the local region you’re in, no matter what.
They have ignored the situation for a long time now, they claimed to have been “monitoring” it but, they never responded after that.
Which never happened, they just ignored the thread until it died