Can not find ads manager/ads center within the FB account on mobile, why?

Hello Friends,

I have 2 FB accounts registered in late 2019, one on PC and the other on mobile.

When I log into the first FB account on PC, I can see ads manager and ads center button on the left.

However, when I check the 2nd FB account on the mobile I can not find ads manager/ads center. What is the matter? Thank you for your attention.

Have you tried to login to this 2nd FB account from some browser, are you able to see ads manager this way?