Procedure for User Stamp (classic)

Press [Edit / Stamp].

Press [Stamp] twice.

Press [User Stamp].

Select the stamp you require.

Press [Change].

Select the stamp position, and then press [OK].

Press [All Pages] or [1st Page Only] to select the print page.

Press [OK] three times.

For details about stamp positions, see Stamps.
You can change the settings for User Stamp under [User Stamp] in User Tools. For details, see User Stamp (Copier / Document Server Features).