How can I get a affidavit of support notarised/apostilled in stavanger

I have been advised by the philippines embassy to get an affidavit of support notarised and apostilled to declare that I am able to support some visiting relatives for the duration of their stay.  The embassy in Oslo said I could do it here in Stavanger but did not know specifically where to go.  I have the form, but do not know how to get it notarised/apostilled if this is 2 processes or if one place does both.  Has anyone been through this process?