In case he comes, please phone me.

如果他来的话，请给我打电话。

youdao

"Please phone me if there's something I can do," I said emptily.

“有需要我做的事请给我来电话吧，”我茫然地说。

youdao

Please ask permission from whoever pays the phone bill before making your call.

打电话前请先征得话费支付人的许可。

《柯林斯英汉双解大词典》

'I am sorry your enquiry cannot be dealt with at this number, please phone...

BBC: THE UNANSWERED CALL

Put the word Ethics in the subject line, and please include a phone number where we can reach you.

NPR: Family Pauses over Woman's Posthumous Request

If you are not sure about the potential charges for accessing the internet on your phone, please ask your mobile network provider.

BBC: News on your mobile