external_url is set to my domain , but in the responses i still see http://localhost:8000

[amitAdnimation]

I am updating the version of my self hosted server,
in config.go file I've set this like in the old instance
v.SetDefault("external_url", myurl.net")
for some reason this is an example response i get

{"id":"xxxx","imp":[{"id":"xxxx","banner":{"format":[{"w":300,"h":250}],"w":300,"h":250,"topframe":1},"bidfloor":0.15,"bidfloorcur":"USD","secure":1,"ext":{"appnexus":{"placement_id":xxxx},"gpid":"xxxx"}}],"site":{"domain":"xxxx","page":"xxxx","ref":"xxxxx","publisher":{"id":"xxx","domain":"xxxx"},"ext":{"amp":0}},"device":{"dnt":0,"ua":"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/127.0.0.0 Safari/537.36","sua":{"browsers":[{"brand":"Not)A;Brand","version":["99"]},{"brand":"Google Chrome","version":["127"]},{"brand":"Chromium","version":["127"]}],"platform":{"brand":"Windows"},"mobile":0,"source":1},"h":911,"w":923,"language":"en"},"user":{"ext":{}},"at":1,"tmax":1500,"source":{"tid":"xxxx"},"regs":{"ext":{"gdpr":0,"us_privacy":"1---"}},"ext":{"appnexus":{"hb_source":5},"prebid":{"channel":{"name":"pbjs","version":"v8.39.0"},"debug":true,"server":{"externalurl":"**http://localhost:8000**\",\"gvlid\":0,\"datacenter\":\"\"}},\"schain\":{\"complete\":1,\"nodes\":[{\"asi\":\"xxx\",\"sid\":\"xxx\",\"hp\":1}],\"ver\":\"1.0\"}}}"

externalurl":"**http://localhost:8000 is still localhost why? is it gets overridden somewhere?
thanks