How to decrypt the cipher-text generated by RC4 stream cipher?

I am encrypting 'text' message using keystream generated by RC4 stream cipher. But while decrypting the ciphertext generated by RC4 cipher, I am not getting the exact plain-text. I have attached my code.

%% \***---*** Text Encryption & Decryption using 'RC4' stream cipher ***---***/ %%
plain_text = 'MatLab R2020a';   
P = double(plain_text);
S = [123, 34, 255, 76, 89, 155, 53, 0, 3, 82, 19, 45, 76];    % Keystream generated by RC4 
E = bitxor(S, P);            % Encryption
cipher_text = char(E);   % O/p in text form
disp(cipher_text);
%% ************* For Decryption; You need keystream S and cipher_text ***********
d_cipher_text = '6C 8ùR1b!-';   % cipher_text copied from 'Workspace'
dP = double(d_cipher_text);
dE = bitxor(S, dP);       % Decryption
dec_text = char(dE);    % O/p in text form 
disp(dec_text);
%% Conclusion: plain_text and dec_text are not same!!