Best way to create groups of triplets

Hi.
I'm kind of new to MuseScore, but I've started to copy some downloaded PDF-music sheets just to get the hang of it. Now the turn has come to the first movement of Beethoven's Moonlight Sonata and the first question that pops up, is how should I go about typing all the triplets, without having to manually mark three eight notes at a time to make them into a triplet? The preferred way would be to tell the software that "Hey, I want the next N notes that I type (ideally using the keyboard and just type the note) to be triplets - and please place them in groups of three notes automatically.

Is there a way to accomplish this? Either as described above or by just typing a bunch of regular 1/8-notes in a row and then mark all of them and automagically group them into triplet-groups?

Any help is greatly appreciated.

Best regards

Stig M.

Best regards