I never seem to be able to choose ping to top up my account. Help please

Can only add four photos to my listing using an oppo phone. Have gone to edit, but it won't let me add more. Tried looking for promote but that doesn't show up anywhere on my phone either.

Someone made an offer on my auction. How long do you have to accept it and how do you accept it? The offer is now not there? but I couldn't see how to accept it.