I can;t display custom fields in the frontent

Hi there, I have been created two custom fields with acf and I want to display them in every post in the front end in two diferrent places (after post title the first and after excerpt the second) with labels explaining each value. Also the same when posts displaying in blog archive posts. I added the code below (only for the first custom field) in the file content.php under the post title section. I am not familiar with coding and I need your help please!

            $custom_field_value = get_field( 'syggrafeas' );
            if ( $custom_field_value ) {
                echo '<div class="custom-field-label">Συγγραφέας:</div>';
                echo '<div class="custom-field-value">' . esc_html( $custom_field_value ) . '</div>';
            }
            ?>

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