I accidentally send to a member 5 love bug hearts I'm playing on my phone how do I send one each and not whole five also the member gave them back :))))

split stack

You can either do it by holding shift, clicking the item, then clicking and empty space in the inventory (if on computer)
or, and this is the relevant one since you're on a phone, you click the item stack that you want to split and then hit this little button: (which is to the right of the 'send item' button)- it will then look like . At this point, you click an empty inventory space and it'll bring up the split stack popup