Sony Xperia XZ2 Manual page 168

Handset dials number. Call begins when other party answers.
Calls to Landline Phones/Cell Phones in Country of
Stay
Place calls the same way you would within Japan.
Do not enter country code or omit first 0 from phone numbers.

In Home Screen,
Phone opens.
xperia-xz2_12_Global Services.docx
4
(Apps) (Phone)