I'm using iOS developer account which is not enrolled(not paid) in program. However, I was invited in Itunes Connect to be developer of company account, so my role in Itunes Connect is developer.
Now I need to upload application build into TestFlight on Itunes Connect, but I can't archive it because of missing provisioning profile in xCode for this application. As my account not enrolled I don't have option to generate distribution and development provisioning profiles in developer page. So I requested company manager to provide me: distribution and development profiles. Receiving them I found that they are with .cer extension and XCode don't recognize them. May be thats because there are only valid for Apple ID owner of the creator.
I read all Apple documentation on this topic, but this issue is not covered or I didn't found it.
How can I get provisioning profiles in this situation? And then upload build into Itunes Connect for app that I'm only developer. Do I need to enroll my developer account? Or company have to invite my in other place?
The .cer only contains the certificate used to sign the binary as the company. It should open in the Keychain Access app, not Xcode. You need to ask the representative to also send you the .p12 file, which would contain the private key for the certificate. Without that private key, you can't build an app as the organization you are working with.
Once you have those, you should be able to log into the Apple developer site and download the provisioning profiles for iOS Development and iOS Distribution. Those should open in Xcode. Once you have all 3 things (the private key, cert, and provisioning profile), you should be able to build the app.