I managed to cancel code to reset the radio for my Toyota Corolla 2007 Ascent after I changed a new battery. What should I do now with 3 lines --- appear? Do I have to key in my own choice of numbers?

The 3 dashes indicate that a 3 digit security code is required..... Once the code is entered correctly it will be unlocked for use! You will not be able to reset the code as it is factory set.

Toyota ascent are fitted with different radios during the model production run

the glove box owner manual should have a card with a 3 or 4 digit number you enter into the radio
.if missing contact or take the ascent to a toyota service center and you get the correct code using the vin number