Thank you for reaching out. There are two ways you can change the research poster to landscape mode. First, if you are a premium user, you can choose the poster and go to the "resize" option; there, you will see a "landscape" mode. Please refer to the below screenshot.
The other way is you can go to the home page of CC Express and click on +sign; then, you will see the below option, then proceed accordingly.
Please let us know if you need any further assistance. We will be happy to help.