One of the ways you can assign payments to expense accounts in Reconciler is by creating a rule to automatically assign payments to an account when they are created.
Step 1 - Go to "Reconcile" view
Step 2 - Find the specific payments on the right portion of the screen that you want to assign (Use any necessary filters)
*Example: Searching for "Microsoft Bing Ads"
Step 3 - Click the down arrow to display additional actions on the payment you want to use and click "Create Rule"
Step 4 - Leave "Auto-Assign Account" selected and select the specific account that you would like all future payments to be assigned to. Determine if the rule should apply to an exact match or needs to just contain the specific details and then click "Add".
*All future payments that match this rule will now be automatically assigned to the specific account.