Plugin no longer works, getting error in console

[mitchar]

Uncaught TypeError: Cannot read property 'querySelector' of null
at GitLabTree.obtainMetadata_latest (inject.js:109)
at GitLabTree.obtainMetadata (inject.js:92)
at new GitLabTree (inject.js:34)
at checkSiteChange (inject.js:479)
at inject.js:482
GitLabTree.obtainMetadata_latest @ inject.js:109
GitLabTree.obtainMetadata @ inject.js:92
GitLabTree @ inject.js:34
checkSiteChange @ inject.js:479
(anonymous) @ inject.js:482
setInterval (async)
(anonymous) @ inject.js:482

[SathishkumarThangavel]

Getting below error as response
{"error":"API V3 is no longer supported. Use API V4 instead."}