I have three battle net accounts .It’s only let me play online on one. Is the other two I get authentication error please try again.
Read Blizzard’s End-User License Agreement a.k.a EULA
You’re not sepose to play more than one instance of the game on one device, blizz even implemented measures to the warden to issue a ban to whoever succesfully tackles the security measures preventing launching more than one instance of the game on a single device…
My advice?
wanna play more than one accout at a time a.k.a Bo Barb in town + a mule ( as eula allows up to 3 battlenet accounts per person), go buy a relatively cheap mid range windows 11 tablet.
dell with 8th gen intel processors + 8GB of ram should be a perfect candidiate.
those come with m.2 drive so if they drive fail you can simply replace the drive instead of throwing away the tablet. that’s #1. #2 is that you could upgrade to NVMe drive to furhter increase the gaming efficiency. and lastly to fulfill GPU requirements you simply need to upgrade intel gpu drivers to the latest for “intel 10th gen GPU and older” and you’re set. Just remember to set the graphics asap to low and resolution 1280x720 and 50% scaling not to overheat the GPU and you should be fine…
there is no other eway to legally play the game on multiple accounts, besides owning multiple machines to run 1 instence on each.