The tweet mentions that it is hard to find XSS vulnerabilities unless you can bypass the Web Application Firewall (WAF). The mentioned XSS payload is <script>alert(1)</script>. More information about the WAF vendor is not provided in the tweet. A blogpost can be created to discuss the importance of WAF bypasses in finding vulnerabilities and the specific XSS payload used in this context.
For more insights, check out the original tweet here: https://twitter.com/OludareEzekiel9/status/1892675088396284221