The "No products available" alert means you have no products entered in your Repsly account or none of the products in your account are active. To enter a new product in the Repsly follow How to add products into Repsly
No Products Available
After making sure you have entered the product data and that the products are marked as "active", synchronize the Repsly mobile app and try again.
If products are checked as active in the Backoffice, then representatives will have a list of product groups available to them when filling out a purchase order.