Wix REST API within Velo

If you don’t mind me asking. what REST API are you calling, and can you provide a code example? This seems like it should be dirt simple but there are undocumented required fields for the draft-post API. I’d like to get something/anything to work at this point. But this just throws a 500 error.

import wixSecretsBackend from 'wix-secrets-backend';
import {fetch} from 'wix-fetch';

export function addOOS(){
    wixSecretsBackend.getSecret("ManagerOOSPosts")
    .then ((mySecret) => {
        const fetchOptions = {
        method: 'post',
        headers:  {
            'content-type': 'application/json',
            'Authorization': mySecret,
            'wix-account-id': '3ce23514-62b3-4167-a04a-ad0b131b09e9', 
            'wix-site-id': 'cdf3c1b4-d8d7-45c0-9c7d-d29b1e7040a8'
            },
        body: JSON.stringify({
            'draftPost': {'title': 'Order of Service - Draft'},
            'publish': false,
            'fieldsets': [],
            'fieldMask': []
            })
        }
        
        fetch('https://www.wixapis.com/blog/v3/draft-posts', fetchOptions)
        .then( (httpResponse) => {
            console.log(httpResponse);
        })
    })
}