What’s the te-form for Owarimasu??? 🤔🤔🤔

I am learning the transitive (他動詞) and intransitive verbs(自動詞) for my Japanese. I got stucked with the correct te-form (て形) for a verb: finish (終わります, read as: owari masu). So I ask Hubby: “Eh, do you know what’s the correct vocabulary form (辞書形) for this word?”, from the vocab form I could figure out the…