Use JavaScript to replace all characters in string with "p" except "o"

I would like to replace all characters in a string myString with "p", except "o".

For example:

"fgyerfgehooefwfweeo"

should become

"pppppppppoopppppppo"

I tried:

myString.replaceAll('[^o]*/g', 'p')

• Pass a regular expression literal instead of a string to replace (or replaceAll).
• Do not use * after the character class; otherwise, multiple consecutive characters that are not "o" will be collapsed into a single "p".

let str = "fgyerfgehooefwfweeo";
let res = str.replace(/[^o]/g, 'p');
console.log(res);