Bing posted a new microsite or portal just for the two newish APIs that allow you to submit URLs for indexing to Bing and also to submit your content for indexing to Bing. The new portal is at bing.com/webmasters/url-submission-api.
These are not new APIs, but Bing is trying to promote them a bit more. A year ago, Bing released the URL indexing API and strongly recommended sites to use it. Then months later, Bing released a content submission API for you to submit your content directly to Bing.
Here is a screen shot of part of this portal:
— Fabrice Canel (@facan) March 20, 2020
I use the url submission API here for Bing, by the way. I have been for several months.
Forum discussion at Twitter.