thanks for reporting this.
Seems that spatialreference.org admins recently made some changes to their server, which now requires additonal certification, ooof.
I will try to fix the WKT components asap.
In the meantime, you can still get the WKT strings for each spatial referance system manually at https://spatialreference.org/ref/.
Just find the CRS you need and open the ESRI WKT definiton (as ie. here) and use them in the same way as you would use the WKT components output.