A cry for help regarding Micropub+WordPress

I’m wondering if any techy people out there can help me with my Micropub plugin.

I’ve installed it on WordPress without any problems, but when I try to use Quill or OwnYourGram, I keep getting the same error message. I tried using micropub.rocks to test out the connection, and the same error message shows up:

I don’t understand what any of it means but in the Micropub FAQ section, they mention this:

If your Micropub client includes an Authorization HTTP request header but you still get an HTTP 401 response with body missing access token, your server may be stripping the Authorization header. If you’re on Apache, try adding this line to your .htaccess file:

SetEnvIf Authorization "(.*)" HTTP_AUTHORIZATION=$1

If that doesn’t work, try this line:

RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization}]

I did that, and my error message from Quill turned into this:

HTTP/1.1 100 Continue

HTTP/1.1 500 Internal Server Error Server: nginx/1.12.2 Date: Sat, 28 Apr 2018 06:32:25 GMT Content-Type: text/html; charset=UTF-8 Transfer-Encoding: chunked Connection: keep-alive

Since that didn’t work, I reversed the changes I made and followed the next instruction on the Micropub FAQ:

If that doesn’t work either, you may need to ask your hosting provider to whitelist the Authorization header for your account.

This took a week of back and forth with my hosting provider (Bluehost) as most of their first level customer service agents have no idea what I’m asking them. Finally a technician gets back to me to tell me that they can’t whitelist the authorisation header for my account.

So the final piece of advice on the Micropub FAQ:

If they refuse, you can pass it through Apache with an alternate name, but you’ll need to edit this plugin’s code to read from that alternate name.

I’m afraid this is way above my tech level. Can someone help walk me through it?