You need to ensure that you have added your trainer as your contact before you can perform the actions below.
To send a message to your Trainer follow the steps below:
Step 1: Log in to your account.
Step 2: Click on the message icon located at the top right side of the page beside your (Profile Name) to toggle the messaging drawer.
Step 3: Make sure that you have added your trainer as one of your contacts before you can find them on your Contact list.
Step 4: Look for the trainer's contact name from the list then click on it.
You can now send a message to your trainer.
You can also see other settings in the dots icon at the right side.
You may click the arrow to send a message.