Assuming you are using the object method of serving the image, specified here https://www.advancedcustomfields.com/resources/image/ Just ammend the code example given by ACF, to include the srcset function:
Original code:
<?php
$image = get_field('image');
if( !empty($image) ): ?>
<img src="<?php echo $image['url']; ?>" alt="<?php echo $image['alt']; ?>" />
<?php endif; ?>
With this plugin’s srcset function:
<?php
$image = get_field('image');
if( !empty($image) ): ?>
<img src="<?php echo $image['url']; ?>" <?php echo tevkori_get_srcset_string( $image['id'], theLargestImageSizeNeeded ); ?> alt="<?php echo $image['alt']; ?>" />
<?php endif; ?>
theLargestImageSizeNeeded is the name of your image size, e.g. medium/large.
Untested, but this should work.