Our app is working with eCom but not with Retail / Omnichannel customers

Hi guys,
we build a multi-carrier checkout integration app for your platform which works for eCom customers. But as soon as a Retail customer using the Omnichannel platform our app is not working. They can't connect.
What is the solution for these type of customers? We need to know if it is possble to extend our app. And if possible where to find the (combined) proper documentation for it.
This is option very convenient for retailers at the moment (because of covid-19) and it would be nice to have a solution soon. Because we can not help them now.
Looking forward to your answer!
Answers
This is probably due to the limitations placed on product and related api endpoints when a customer is using omnichannel. It's pretty clearly documented here: https://developers.lightspeedhq.com/ecom/introduction/omnichannel/
Matt Anger
https://spectraretail.com/
Thanks Mattanger
we will check. If we have questions we will let you know.
regards Jeroen
Hello Mattanger,
we have tried several solutions but still getting this error (see att).
The system is not sending any error information to guide us in the right direction. Can you let me know how we can sove this issue asap? Maybe email (DM) contact to sent you some parts of our code?
Looking fwd to your answer.
Regards Jeroen