featured image size

hi

i could import featured image with enclosure tag.
but image size is small than target Html.

inserted 0;1000

how can i fix this?

my post page————-
https://miraiagent.co.jp/2019/01/20/monster-energys-pat-casey-wins-first-toyota-bmx-triple-challenge/
————-
featured image (24KB 110×23 is small than target html’s image)
https://miraiagent.co.jp/wp-content/uploads/2019/01/811733619c.png
————-
Target post page(original image size is 107 KB)
https://www.prweb.com/releases/monster_energys_pat_casey_wins_first_toyota_bmx_triple_challenge_teammate_andy_buckworth_takes_second_place/prweb16046903.htm