Couldn’t find my transaction I bought bitcoin from Simplex two days ago but now when I check the blockchain.info website I face to "No transactions found for this address, it has probably not been used on the network yet" error. I will really appreciate it if someone can help me. Is that normal or maybe the problem comes from the seller?

Thanks
Check the transactions section in you dashboard else contact the technical support.
here is the answer i found in their website : https://www.simplex.com/faq/

Usually, payments are processed within the hour; however, some cases require more attention and can take up to 24 hours to be approved.  You will receive an email once your payment has been reviewed.

If your transaction is still pending, it might be because you have yet to submit to a verification request.
In such cases, an email is sent asking for proof of identity or card ownership – which can land in your spam folder. In case of delays, please check your spam folder for a verification email.