Under 'My eBay Plus' go to 'edit membership' and cancel. Follow the prompts and you should get a $30 Gift Card.
I chose too expensive, but I really wanted to say sellers jack the prices during percentage off sales!
I just did it today (28 Apr 22 for an account renewing on 4 May)
https://www.ebay.com.au/ebayplus/home
Its a $30 Ebay Gift Card ( not $30 voucher )
https://pages.ebay.com.au/ebayplus/30-renew-membership-gift-…
My payment hasn't gone through yet, so I can only assume it'll come through by email after mine renews.
Thanks to superbass, see also https://www.ozbargain.com.au/node/692723 for possible stacking of retention & sign-up offers.
plus also credit/thanks to @CodeXD:
Direct link to this deal - it will automatically sign you up.
ONLY CLICK THIS WITHIN 3 MONTHS OF YOUR EBAY PLUS MEMBERSHIP EXPIRING
How was it delivered and how long did it take?