I finally solved it.
It seems that I wrote the shortcode of the form on each page, and when I deleted it, the lostpassword page was displayed and I was able to reach the resetpasss page.
Thank you.
Is it better to use the paid version?
I will explain in detail so please teach me!
I made a resetpass and checked the display.
Then, if you put resetpass in the Theme My Login settings, the resetpass page will be redirected to lostpassword.
Why is it redirected to ***.com/lostpassword when I create ***.com/resetpass?