I requested a travel voucher online from KLM on 3rd April. The system message said it could take "more than a week".
1 to 2 weeks wait would be fine by me. I'm not going anywhere. But some posters have said that they needed to follow up with a phone call to AF/KL to get the voucher.
I'll wait for 10 day working days and then call them.
The phrase "more than a week" could actually mean three months!