Cannot Access Dimensions Tab with Clean Journal Pro Theme

Hello there, I cannot access the dimensions tab in my Clean Journal Pro theme. I am having an issue with a lot of added space showing up between the headline of my posts and the first block and I am not able to remove that space because I am not able to access the Dimensions tab in Wordpress using the Clean Journal Pro theme. Question: Does the Clean Journal Pro theme support the Dimensions tab when using Blocks? Please advise. Thank you so much! Robert Wesley Branch