The steps to make a missionary donation online are:
- Sign-in to LDS.org
- Select "My Account and Ward"
- Select "Donations" from the middle column under the "My Ward" column title
(You will be redirected to the LDS Account sign-on page if you did not accomplish the sign-in at step 1)
- Click the down arrow in the "Ward Missionary Fund" field for a list of serving ward missionaries from your ward
- Select your missionary and then enter the donation amount
Your missionary's name may not appear on the list yet since it requires action from the Missionary Department to get the name on the list. It should appear some time this month. If it is not showing now you can either wait until it does appear or you can make a paper donation slip donation to a bishopric member.
Since it is only 1 October and a Monday today, I doubt it will take more than a few days for your missionary's name to appear on the list.
Monthly equalized payments are pulled from the ward missionary fund during the second week of the month so I would expect your missionary to be on the list by that time. If it does not appear by that time then contact your ward clerk so he can contact the GSC (global service center) and/or the Missionary Department to see what is happening.