The asposehtmlcloud package does not seem to be usable because it is unable to complete the authentication flow to get a bearer token.
It appears this was broken in this commit https://github.com/aspose-html-cloud/aspose-html-cloud-nodejs/commit/c6310739f0d55ba7441e2d6b0178952c94ed6060#diff-412eda8bdcccd6b1a45c25c9647614d1R125
Strings here are immutable and concatenating strings does not maintain a reference to the component strings, which means the logic there does not work. Although
this.accessToken is updated with the bearer token,
this.defaultHeaders.Authorization is not updated because it has no reference to
The impact of this is that all API requests are made with an Authorization header of
Bearer undefined and therefore they return an error.