Start with wheel balancing, then check it and any spacers are seated properly(clean out the hub hole of the rim), then check steering bushes inc lower wishbone.
If you've got or can borrow a space rim with tyre try it on each side front to see if it cures it. It wil rule out bushes, bearings etc.
3Wheels3 had similar yesterday and we thougt it was buckled rim but turned out to be badly mounted rim/spacer.
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