Tear in my seat cover. What can I do?

You can pull the seat, you can pull the back row of hog rings that hold on the vinyl.

Hand, Baste stich it back together from the back side.

Repair finished, hog ring the vinyl onto the seat frame again.

Now you are an upholstery guy.

View attachment 1716064692

Sew like this, back side.

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that stich will tear the vinyl back out in one use, you would be called a hack trimmer and never have any repeat customers if you did that.