Once logged in to https://instagram.com/developer, start by clicking 'Register Your Application'
You will be asked to give some information about your website, your phone number, and a brief description of what you are looking to build. Completely fill out all information requested, and ensure that the URL you enter for your website is the full URL that you are currently using for your marketplace (if you have not created a custom domain, use your Near Me subdomain - e.g. https://example.near-me.com, but please note that you will need to edit this URL when you do add your own custom domain)
From here you will need to register a new client. To do this select, 'Manage Clients' at the top of the page.
On the following page, you will have the option of registering a new 'client' - or in our case, the app that you are creating. Click on 'Register a New Client' in the upper right corner of your screen
You will be asked to fill out the information needed to create your app, including a name, description, and URL/redirect URL. For the URL and Redirect URL, be sure to enter the full domain that you are using for your marketplace. Example https://tradeya.club for URL and https://tradeya.club/auth/instagram/callback for the Redirect URL. Scroll to the bottom (don't forget to fill out the CAPTCHA) and select 'register'. You will be taken to the page where you are given the keys that you need to integrate Instagram (i.e. 'Client ID' and 'Client Secret')
To navigate to the Instagram API keys, you'll need to click on "manage"
You'll see "Client ID" and "Client Secret" at the top
Navigate to Admin Dash > Settings > Integrations and pull the appropriate code from the Instagram page into the fields below.
When you launch your marketplace you will need to update the URL to reflect your custom domain, don't forget or it will break your integration!
To Go Live: "To get out of Sandbox mode, you need to submit your app for review. If your app falls into the approved use cases and gets approved, it will automatically go live. At this point any Instagram user will be able to authorize your app, but you will have access only to the permissions that you were granted during the review. If you need access to more permissions, you can submit for review again and you will not lose access to the permissions that you have already been granted."