post https://api-sandbox.aurorasolar.com/tenants//designs//web_proposal/generate_url
Generates a new Web Proposal URL for a design.
Generates a new non-expired url for the Web Proposal (To get more information on the Web Proposal expiration time, please contact your Aurora account team).
This will immediately expire any previously generated Web Proposal url, even if the previous Web Proposal url wasn't expired. A Web Proposal can only have a single non-expired url at a time.