You need to use your LDS Account to sign into LDS tools on your iPhone. Do you need your LDS Account password reset? (If you don't know, try going to LDS.org and signing in from the Sign In/Tools menu at the top right...if you can sign in, then it's the same password for your iPhone.) If you need to reset your account, go to ldsAccount.lds.org and choose
Can't Sign In. You should receive some help.
I'm not sure what calling you have, but you mentioned passcode, so maybe you have a leadership calling with access to sensitive data that requires an additional passcode? If that's your question, I suggest looking in the
LDS Tools forum for iPhone. I did a quick search and found
this thread that might answer your questions.