Feedback on my solution of Intermediate Algorithm Scripting - Sum All Primes

Tell us what’s happening:
Describe your issue in detail here.
i feel my code is not efficient code because it needs alot of steps to excute to come up with the solution so tell me how can i improve it ??

  **Your code so far**
function sumPrimes(num) {
let j=2;
let arr = [];
let sum =0;
while(j <= num){
  let isPrime = true;
  for(let i =2;i<num;i++){
    if((j/i)%1 == 0 && i !=j){
       isPrime = false;
       break;
    }
  }
  if (isPrime == true){
    arr.push(j);
  }
  j++
}
for(let i=0;i<arr.length;i++){
  sum += arr[i];
}

return sum;
}

sumPrimes(977);
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Challenge: Intermediate Algorithm Scripting - Sum All Primes

Link to the challenge:

If you need a faster solution look into this
article Sieve of Eratosthenes - Wikipedia

If your code works, this is one challenge where I’d check out the solutions.

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