What is the rule? And wat are the next two numbers of the pattern

So, the next two numbers are 55 and 89

So,

1+1=2

1+2=3

2+3=5

Starting at the 1,1 add them together to get the next number which is 2. Then 1,2 add 1+2 to get the next number which is 3. Next, 2,3 add 2+3 to get the next number which is 5

I hope you understand that. I tried to explain it at the best of my ability