Online/offline switching

Please let us be able to switch off-line to online because I want to be able to play with my friends but I can’t. I had no idea that if you picked off-line you couldn’t change it and now I’m kind of annoyed about it and I have a lot of progress on the off-line hero and I just really wanna play with my friends, but I just can’t cause you guys just decide to lock it for no reason so please let us be able to switch off-line heroes to online heroes .