help understanding the wpa handshakes that pwnagotchi captures

I tried to test some handshakes that i captured but had no luck with hashcat. So I thought I would try them using https://www.onlinehashcrack.com/wpa

I submitted the pcap file but that site said:

"No valid EAPOL handshake or PMKID found in the submitted file."

I am new to testing this stuff. I captured some handshakes with a pwnagotchi and others using wifite in kali.

How can I tell if the pcap file (or the converted hccapx file) is worth using against hashcat? If pwnnagotchi captures something, does that mean it is a valid handshake if I find it in the handshakes directory of the pwnagotchi?

The issue mentions pcap captures, converted hccapx files, hashcat, and the pwnagotchi handshakes directory; begin by reviewing those artifacts and the capture workflow described in the repository. Done would be a clear explanation of how to distinguish usable captures from invalid ones, including validation steps for newcomers.

Written by the indexing model from the issue text.