To be able to connect a Instagram account it will need to be a business account.
How to make a business account
Firstly click on the Instagram icon here
Once you've clicked on connect a profile you'll get redirected to a screen like this
You've got two options on this screen, you can continue as the account signed in or you can "Log in to another account."
You'll then be presented with a screen like this, check you're happy to continue and then click 'get started'.
Meta rules require your Instagram account to be connected to a Facebook page to be able to be linked to Sisoma.
Next, sign into your Instagram account.
Now you're signed in you'll be presented with your professional accounts to select. Select the account you want to use with Sisoma.
and you're all done, you should now be able to see that your Instagram account is connected.