New Site Self-Hosted ActivityPub using Docker Fails. Gets HTML response.

[tristanisham]

18:08:52.221 INF activitypub: 'GET' 'example.com' 'https://example.com/.ghost/activitypub/v1/blocks/domains' '7969707b-df56-43ce-a72f-2898c7835eb6' 500 2324ms
18:08:52.392 INF activitypub: 'GET' 'example.com' 'https://example.com/.ghost/activitypub/v1/notifications/unread/count' '7642d4e5-28fb-4a52-af06-aea3dca3d7fd' 500 1919ms
18:08:52.390 ERR activitypub: SyntaxError: Unexpected token '<', "<!DOCTYPE "... is not valid JSON
    at JSON.parse (<anonymous>)
    at parseJSONFromBytes (node:internal/deps/undici/undici:5738:19)
    at successSteps (node:internal/deps/undici/undici:5719:27)
    at fullyReadBody (node:internal/deps/undici/undici:4609:9)
    at process.processTicksAndRejections (node:internal/process/task_queues:105:5)
    at async consumeBody (node:internal/deps/undici/undici:5728:7)
    at async getKey (file:///opt/activitypub/dist/app.js:386:18)
    at async roleMiddleware (file:///opt/activitypub/dist/app.js:428:17)
    at async dispatch (file:///opt/activitypub/node_modules/hono/dist/compose.js:22:17)
    at async dispatch (file:///opt/activitypub/node_modules/hono/dist/compose.js:22:17)

[tristanisham]

I'm following the official guide, have the .env file setup correctly, and have rebuilt everything, including hard relaunching Ghost and Caddy.