Python 3.6.9上f字符串的语法错误

I know there is a similar question here, but it does not solve the problem for me. I'm running Python 3.6.9 on VScode on WSL2 and am getting syntax errors whenever I try to use f strings. Example:

s1, s2 = 1, 2
s = f"blah {s1} blah {s2}"


File "", line 31
s = f"blah {s1} blah {s2}"
SyntaxError: invalid syntax