Whenever I try to record myself singing (don't ask), I use a free recording software for download on iOS. The file saves as .wav, but there are several other free softwares available that you can download and use to record yourself. You can save it as .wav or .mp3 and upload it to your proposal.
Hope this helps!
Your softskills and abilibity to server the customer should be reflected from your voice. You will deal with n number of customers so make sure you have that patience while you`re on a call if you really want to survive in this customer support industry.
Sr. Operations Manager - Apps4Rent