Iphone 8plus

Assuming the seller has disappeared as is typical for these sorts of sales and these questions, yes, you lost your money.

You will have no means to bypass the theft-deterrent Activation Lock mechanism, Apple won’t bypass it without proof of original purchase showing the serial number or IMEI, and which means you’re left to recycle this iPhone.

The All Too Common SAD Reality of Buying a used iPad/iPhone - Apple Community

Kensleemae_13 wrote:

I have a receipt and IMEI

If you have the original purchase receipt from Apple or from an authorized reseller showing the IMEI or serial number, then contact Apple Support.

If you have the purchase receipt from the sale where you acquired this iPhone, or any other intermediate sale, or if have the IMEI, or the serial number, that won’t sufficiently prove ownership per the requirements that Apple uses.

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