Byzantine coin? [解決]

Gold 22mm and 3.54gr any info would be great thx.

Republic of Venice for sure, 1 Ducato or 1 Zecchino but I don't know which period.

This coin intends to be a zecchino of Antonio Venier (1382-1400), like this one: https://en.numista.com/catalogue/pieces33543.html

However, there appear to be some errors in the legend, which makes me question if it is an imitation, possibly a contemporary one used in trade,.

The errors:
Obv legend: AnIO VeNaIQ S M VaNTI instead of ANTO VeNERIO S M VeNeTI
Rev legend: SITT . XPeD . ATa . T eGIS ISTe DVcAT instead of SIT • T • XPe • DAT' • QTV ReGIS • ISTe • DVCAT'

I haven't looked at other published examples to know if this is a known variant, but mis-spelling Venice seems a bridge to far .

What is the origin of this coin?

This coin was found in the sea in Greece

Here is an answer consistent with the circumstances of your coin.

The "Crusader State" principality of Frankish Greece made contemporary imitations of the Venetian zecchino like yours, with incorrect legends. A number of these were sold in an auction in Germany in 2019, which can give you an idea of the value:
https://www.numisbids.com/n.php?p=lot&sid=3194&lot=413

ANd another possibility: https://en.numista.com/catalogue/pieces192693.html

These are consistent with the incorrect legends on your coin, and with the location where it was found.

Interesting thx