Sender shows bitcoin being sent be it can not be found when I look for it in blockchain explorer nor can the send produce a transaction number
When using bitcoin, you don't have to trust anyone to tell you if you received a transaction, you can verify it for yourself.
To do so, you can run a bitcoin 'full node' (such as the bitcoin core software), and then query the node to find the transaction in question.
Failing that, you can check to see if your wallet software has received a new transaction.†
Failing that, you can check an online block explorer service to see if the transaction exists.†
If any one of these methods doesn't reveal the transaction in question (and your software is otherwise all properly synced with the network), then there is no reason to believe the person who said they sent you funds actually did. They may have encountered a software issue, or they may be attempting to defraud you.
†both of these methods involve trusting someone else to do the validation steps for you, but it is perhaps better to trust a third party, that has little economic incentive to defraud you