您需要将以下代码添加到主题的函数中。php文件。如果尚未创建child theme, 因此，当主题更新时，您不会丢失编辑。

Update the Log In text

function custome_login_btn(){
    add_filter(\'gettext\', \'custome_login_btn_text\', 10, 2);
}

function custome_login_btn_text($translation, $text){
    if (\'Log In\' == $text) {
        return \'MY NEW TEXT\';
    }
    return $translation;
}

add_action( \'login_form\', \'custome_login_btn\' );

Update the Register text

function register_text( $translated ) {
    $translated = str_ireplace(\'Register\',  \'MY NEW TEXT\',  $translated);
    return $translated;
}

add_filter(  \'gettext\',  \'register_text\'  );
add_filter(  \'ngettext\',  \'register_text\'  );

这两个功能都经过测试并正常工作。

Edit - 为了你的特别

function login_text( $translated ) {
    $translated = str_ireplace(\'Log In\',  \'MY NEW TEXT\',  $translated);
    return $translated;
}

add_filter(  \'gettext\',  \'login_text\'  );
add_filter(  \'ngettext\',  \'login_text\'  );