Finding truth

The one introducing the SOLE real Joker is telling the truth but cannot be another Joker (one total 🃏), so the introducer must be a Knight, the SOLE one themselves by the sole existence of a Joker 🃏.

Since exactly one of them is a joker and they all accuse different people of being jokers, the joker is lying. If the joker were telling the truth, then they would claim that they themselves are the joker, which none of these three are doing.

Given each person is accused by another, one of them is correctly accusing the joker of being a joker and thus is telling the truth. For instance, suppose that Ellis is the Joker. Then Gobi is telling the truth. Or you can suppose that Farin is the joker, in which case Ellis is telling the truth.

This person telling the truth can't be a joker (since as already pointed out, the joker is lying), so the truth-teller must be a knight.

We've concluded that one person is a joker and at least one is a knight. The third person can't be a knight (they must be a knave), because the knight and the third person are saying that different people are jokers, which is impossible with only one joker. For instance, if Ellis is the joker, then Gobi is telling the truth (and is a knight) and Farin is lying (and is a knave).

So, since there is only one truth-teller, there must be only one knight.

Note: "None of them are knights" is incorrect because one of them is a joker and all of them point to another person as the joker. One of them has to be telling the truth, and it's not the joker.