Wingman_kz
Go to the hardware or auto parts store.
And as a plus, you will find a significant cost savings by purchasing such a generic material vice one with a model manufacturer's logo. Tamiya lacquer thinner will run you about $20 USD per liter while Kleen Strip lacquer thinner from the corner hardware store will run you about $8 USD per quart. Buy a gallon and pour off into smaller containers for even more savings
And as always, test before using a new to you material or process