This is called The Real Heroes Project and has seen some of the top names in women's tennis play their part; including Naomi Osaka, Ashleigh Barty, Bianca Andreescu, Coco Gauff and Victoria Azarenka.
They will cover their name on their jerseys/uniforms; then replace them with the specific hero. As a result of this, they have asked for fans to do the same; then use the hashtag #TheRealHeroes to show their efforts off.
https://twitter.com/WTA/status/1257295229247504391?s=20