You are a sales rep and you have just completed a sales activity.
This may be closing a sale, sending an offer, booking a meeting or another activity.
Now what you want to do next is report this into SalesScreen.

Click on the New button in the menu. Then click on Report.

On the top, you can select the Type of report that you'd like to add. Every company will have their own activity types.

You can then select an Activity and fill in all the necessary information required. When done, click Add to register your report.

If you have activities that are frequently added in this way, you may want to highlight them for your users in the root 'New' menu by making them available to Quick Add.