Just did a fresh install of the 2020 wordpress theme.
In the footer you have the text "Powered by wordpress".
From what I've searched it's supposed to be under "Appearance" => "Customize" => "Footer".
Only problem is that there is absolutely no "Footer" option there at all.
What gives?
EDIT: Tried the other default themes for 2019 and 2017, it's also not there.
Unfortunately, it seems there is no hook to filter the “Powered by WordPress” text in Twenty Twenty.
You could either create a child theme, copy footer.php from the TwentyTwenty theme directory to your child theme directory and remove the “Powered by WordPress” paragraph.
<p class="powered-by-wordpress">
<a href="<?php echo esc_url( __( 'https://wordpress.org/', 'twentytwenty' ) ); ?>">
<?php _e( 'Powered by WordPress', 'twentytwenty' ); ?>
</a>
</p><!-- .powered-by-wordpress -->
Or, you could simply hide it with CSS:
.footer-credits > .powered-by-wordpress {
display: none;
}