Then you can use the AltGr button at the botoom of you keyboard, next to the space bar and the number 6 (for circumflex) at the same time.
Yna gallwch ddefnyddio’r botwm AltGr ar waelod y bysellfwrdd ar bwys y ‘space bar’ a’r rhif 6 (ar gyfer to bach) ar yr un pryd.