Hi,

If you're using Elementor to build that block - you can check option for it on edit that block > and check option for align read more button on "Other Layout Options" section - check this image: http://prntscr.com/vmjglu

If it's on a category page, tag, or archive pages - please check option for it via Customize > Posts Layouts > Other Layouts > Align "Read More" button

Best Regards,

PenciDesign