Peeing

F 1.5 year old Sheppard mixed breed. Got her from a shelter at around 2-3 months old. Potty training is still ongoing but does anyone know how to fully correct going inside? If she is not let out exactly when she wants or on routine she will go wherever she pleases. Today it was the bed. I’ve been doing the treats everytime she goes out and we have bells but how do I make it click in her head that going inside is an absolute no and not an option? She has higher gravity in her urine and is on supplements to help but I just want her to thrive and not be a pee monster inside