Why My Manually Generated Mnemonic Seed Phrase Is Not Recognized by Metamask or Trust Wallet

I used this code to create a random entropy

func randomNumGenerator() []byte {

n := 16
randomByte := make([]byte, n)
_, err := rand.Read(randomByte)
if err != nil {
    panic(err)
}

return randomByte

}

And checksum func checkSum(entropy *string) {

data := *entropy
checkSumLength := len(*entropy) / 32

//Sha256 of entropy
hash := sha256.Sum256([]byte(data))
// hexFormat := hex.EncodeToString(hash[:])

bitHash := byteToBit(hash[:])
*entropy = *entropy + bitHash[0:checkSumLength]

}

We added it to the end of the entropy, halved that entropy into 11 bits, matched it against the 2048 word list, and got the word.

“Sustain Remake Shift Future Stone Merge Antique Denial Divide Century Clay Chalk”

But when I use this word in trustwallet it shows invalid seedphrase

Can someone explain me why? I did all the BIP39 steps correctly in my code