How do I change or overwrite the content of html in a function?

I need to change the input field step from step=”0.01″ to step=”100″ in functions.php of a child theme so that parent theme stays untouched.

Here is the code I am trying to change from my child theme functions.php

<?php
    class WPTRequestsNewFieldsContent {
        public function budget_to( $placeholder = '' ) {

            if ( wpt_get_option( 'wptheme_request_budget' ) == "yes" ) {
                $post_value = WPT_Form::post( 'request_budget_to', get_post_meta( $this->pid, 'request_budget_to', true ) ); ?>


                <div class="ui basic">
                <input
                    type="number"
                    min="0"
                    step="0.01"
                    placeholder="<?php echo $placeholder ? $placeholder : _x( 'The price at which your request ends', 'Post new request', 'wptheme' ); ?>"
                    id="request_budget_to"
                    value="<?php echo $post_value; ?>"
                    name="request_budget_to"
                />
                </div>

            <?php } else { ?>

                <div class="disabled-field"></div>

            <?php }

        }
    }
?>