employer change on H1B while at home country

[JMDJSS22]

Dear Experts,

I have stamped H1B visa with me and I am still in my home country.

Please help me with info on below situation.

My visa is from employer A but now I got a better offer and role by employer B, so could I accept the offer and go for employer change on visa . Could anyone guide me how much time it takes to change employer on visa while at home country.

Appreciate your help.

Thanks
JSS