Can you please explain clearly what exactly is the problem?
An Array of strings in js will render as string with "," in between all elements.
but in react it render without ''," and without space.
here is the code
1) innerText = "mission impossible".split(' ').join().split(', ');
Add a space in the first split and after the comma in the end split. The output is this

is this is what you are asking for?
This isn't a CRA issue, its a react issue and should probably be in Stack overflow
here is the code
innerText = "mission impossible".split(' ').join().split(', ');
Add a space in the first split and after the comma in the end split. The output is this
is this is what you are asking for?
it will work but it should work without adding space.
Most helpful comment
This isn't a CRA issue, its a react issue and should probably be in Stack overflow