To be able to enter Costa Rica you will need to go to https://salud.go.cr/ and fill up the online questionnaire 2 days or less before your CR entry date. If you try to do it before 2 days, the system will not let you do it. The entry date must correspond exactly to your arrival date.
The best will be if you read the required documents list and conditions on that website even before you buy the insurance (which has English option), but just for convenience here are the main points:
You will need
– your passport details
– the airline information
– the reserved seat numbers from your ticket or check-in if you didn’t reserve them
– health insurance policy that covers COVID cases
– address of your stay in Costa Rica
If you bought insurance from Costa Rican (CR) companies Sagicor or Grupo Ins, you will need only the policy number. If you have it from a different insurance company or from outside CR insurance provider, you will need to scan and upload the entire policy. Make sure the scanned file is no more than 5 MB and is in one of four accepted formats: PDF, PNG, JPG, GIF. If you received your insurance via email in PDF format, it will be the smallest possible size and you better use that one, just save in your documents and upload from there. If you have to scan the document use no more than 200 dpi resolution. If you do not have a scanner, the easy way is to use Office Lens application on your smartphone that will give you nice rectangular scans. Then there is always Staples (or a friend) where you can get your documents scanned and saved on a USB drive, if nothing else can be done.
One important note: when you finish the application, the system displays the barcode. You can request an email to be sent to you, but because sometimes the emails might not get to you on time, it is always better to take a picture with your phone and also print it if you can. You will need to present the barcode at the boarding and the passport control in CR. Without that barcode you will be refused to board the airplane.
Safe and pleasant voyage.