A message that says "I am interested in your item, kindly text me", an offer greater than or equal to your buy it now price, asking for your PayPal email address or a request for a gift card is generally the start of a scam where the scammer winds up sending a phony payment email that makes it look like the seller has received a payment when none has actually been received. Scammers like to target new sellers, particularly those selling expensive items.
Sending contact information (text or email) prior to a transaction payment is a violation of eBay policy; this policy is designed to protect honest buyers and sellers from this sort of thing, and to prevent off-eBay sales.
Never buy a gift card for anyone unless you are giving a gift.
As a seller you should always check your account directly (not following a link in an email) to see if you have actually been paid prior to shipping. If a user commits to a purchase but does not send an actual payment, after four full days you can cancel for nonpayment and give the "buyer" a strike. Be sure to set your buyer requirements to reject bids or purchases from users with two or more nonpayment strikes in the last year.
eBay will likely remove the scammer's account shortly, but the scammer will just create a new one or hijack an old one and continue sending scam offers and messages. Sellers must remain wary of any user that wants the seller to violate eBay policy.
After four days you can cancel the transaction for nonpayment to give the buyer a strike and prevent feedback from being left by either party. If you cancel earlier or for other reasons, the buyer will not get a strike.
Add the user to your Blocked Buyer List to prevent that particular user from bidding on or buying any more of your listings, regardless of what other sellers do.
https://www.ebay.com/help/selling/resolving-buyer-issues/blocking-buyer-ebay?id=4082
Be sure to set your Buyer Requirements to preemptively block bids or purchases from users with two or more unpaid item strikes in the last year.
You can avoid many common scams by listing your item for a fixed price with immediate payment required and by not making or accepting any offers. That way the buyer must complete checkout and actually pay in order to proceed.
