how to adjust the volume with a roku express remote?

The express comes with an IR remote. Only wifi remotes have tv controls. If the express is not 3700 series then it can be paired to a wifi remote that has to be purchased separately. 

Thank you for getting us back here in the Roku Community, Cliche1206!

Could you please specify the model of your Roku Express?

Here is a clear explanation of the key differences between the two types of Roku Express and some information about our products.

1. The first one is the Roku Express, which comes with a simple remote without any volume and power buttons. This model only works with the simple remote because it uses an IR (invisible infrared) light to send a signal a short distance from the remote (where the IR transmitter is located) to the front of your Roku device (where the IR receiver is located).
2. The second one is the Roku Express 4K+. This model comes with the Roku Voice Remote that has both power and volume buttons and utilizes a CEC (Consumer Electronics Control) setup. CEC allows commands to be shared between devices over the same HDMI connection as audio and video, letting you control the standard functions of different devices without having to juggle remotes.

For more information about our Roku product, please visit our support website and review the details about Roku streaming players.

We hope this clarifies any confusion and helps you determine which Roku Express model you have and which remote is compatible with your Roku device. If you have any further questions, please don't hesitate to ask.

Best Regards,
Jharra