For example: I have now [ https://www.sub-domain.wordpress.com/22-January-2020/song ] I want to change into [ https://www.sub-domain.wordpress.com/song ]
In here 2-January-2020 is the date of updating the post called song that contains the update date. I just want nothing here.
Remember, this is my free hosting plan with a free sub-domain name.
The default format for post URLs (the permalink structure) cannot be changed on sites hosted by WordPress.com (free hosting). They can only be changed on self-hosted WordPress sites.