Fill gaps from assistant conversations: HighLevel setup and Salesforce namespace

[mintlify]

Summary

Address recurring assistant confusion about the HighLevel provider app setup and the Salesforce Link Namespace step so future readers can complete both flows without asking the assistant.

Changes

• HighLevel provider guide: added the explicit Ampersand redirect URL (https://api.withampersand.com/callbacks/v1/oauth) to the OAuth setup step, so it matches the pattern used in the HubSpot and QuickBooks guides. Also split the "submit for review" note into its own step to make clear that a draft HighLevel app cannot be used with Ampersand.
• Salesforce provider guide: added a troubleshooting note under Link namespace to Dev Hub Org covering the invalid_client_id / client identifier invalid OAuth error. Ties it back to the existing "namespaces cannot be created in the Dev Hub Org" rule and points readers to sign up for a fresh Developer Edition org if Dev Hub was accidentally enabled on the Namespace Org.

Context

Assistant query buckets from the past week showed:

• Users unsure whether a HighLevel app in draft is usable with Ampersand, and no explicit redirect URL on the HighLevel page.
• A thumbs-down thread where a user in incognito still hit invalid_client_id while linking their Salesforce namespace, and the docs offered no next step beyond "try incognito".

Other buckets reviewed (empty-string schedule, BYOC, whitelabel HighLevel highLevelStandard provider) were skipped because I could not verify the behavior or product against the repo without guessing.

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Project	Status	Preview	Updated (UTC)
Ampersand	🟢 Ready	View Preview	Aug 24, 2026, 4:11 PM