This is a very dubious paper.
*Arxiv is a preprint server and isnt peer reviewed
*Critical temperature claims are far above other groups
*Other claims of high temperature superconductivity required high pressures/extreme conditions
*The paper itself has several proofreading mistakes and isnt written in a professional manner
*No replication of claims
*The material is a Copper substituted Lead II phosphate which is... questionable
There are just too many things about this paper that raise alarm bells.