Similar to last year's promotion
As per the comments, the offer appears to be open to both new and existing users of the app.
To claim the $10 voucher:
Using a smartphone compatible with Samsung Pay, download and activate Samsung Pay
Activate the offer under 'promotions'
Upload at least one Eligible Card into Samsung Pay on your Device.
“Eligible Card” means a debit card, credit card or loyalty card supported by Samsung Pay in Australia - this includes cards such as Flybuys, Woolworths Rewards etc
Eligible Devices include any of the following Samsung Galaxy devices:
i. S6 (SM-G920I);
ii. S6 Edge (SM-G925I);
iii. S6 Edge+ (SM-G928I);
iv. Note 5 (SM-N920I);
v. S7 (SM-930F);
vi. S7 Edge (SM-G935F);
vii. A5 (SM-A520F);
viii. A7 (SM-A720F);
ix. S8 (SM-G950);
x. S8+ (SM-G955F) and
xi. Note 8 (SM-950F);
The first 35,000 Eligible Claimants who submit an Eligible Claim will receive a pop-up notice in Samsung Pay confirming they are a Winner and a including a voucher code using which the Winner will be about to receive the Gift. "Gift" means a voucher valued at $10.00 which can be redeemed at Woolworths supermarkets in Australia or on www.woolworths.com.au.
Found the app was already installed. Just had to search for it. Redeemed voucher and all is good.