How would people use this tax credit that is printed on the receipt for every supermarket trip they take? It doesn't sound even remotely practical.

What about if stores credit customers n cents per bag they don't use (i.e. for each reusable bag they do use) and then claim an annual tax credit, kind of like a mirror version of how pass-through consumption taxes like GST/VAT work?

How about putting the tax up front while the customer is on the register? It reduces the burden of documentation for both the customer and government while also ensuring near 100% compliance. Might be a good idea to look into.

A better solution would be to pan the production and use of disposable plastic bags altogether like most countries did with plastic microbeads.

There's no good reason to ban plastic bags. We have to take convenience and quality of life for humans into account at some point when considering these environmental issues.