Well, this is the trouble with taking one isolated verse as if that would indicate "here is proof that the later Trinity doctrine must be false!"
Just read a few verses on, and Jesus identifies himself as the long-promised Messiah who will explain the Father. Up till then, this Samaritan woman had been labouring under misunderstandings about worship of God; Jesus began to deal with those errors, and by the time he has been crucified, resurrected, and ascended to heaven, those who believe him to be the Messiah are acclaiming him as their Lord and their God.
Chalcedonian trinitarian Christians can reel off a long list of scripture texts where Jesus mentions himself as key to gaining understanding of the Father; as key to offering acceptable worship; as key to having the Father and the Son love those with faith in them, so that they will indwell them. I have to close down now, but by the time I re-open next week, you may wish to request those myriad verses where Jesus shows himself to be God incarnate - or, maybe not. I shall check in later to see. Perhaps someone else will spare me hours of work providing such a list by giving their own answer.
EDIT as requested: Repetition For Emphasis: - "Just read a few verses on..." starting with the very next verse in the text asked about, i.e. verse 25 through to verse 42 (which ends with all the villagers saying they now believed in Jesus, "for we have heard him ourselves, and know that this is indeed the Christ, the Saviour of the world.")
In those verses, Jesus speaks about himself, though not in verse 23. But he clearly calls himself "the way [to the Father], the truth, and the life" in John 14:6.