The correct certificate to download is the DigiCert Global Root CA, which is valid for several years and can be downloaded from api.thingspeak.com using a variety of different web browsers. Below are directions regarding how to download it using common web browsers:
Google Chrome
1) Visit the api.thingspeak.com website, and click the settings icon on the left of the address bar:
2) Click Connection is secure > Certificate (valid):
3) Click the Details tab, make sure the DigiCert Global Root CA is highlighted as shown below, then scroll down and click Export:
4) Save the certificate to your computer. You will have the option to save the certificate under multiple file types:
For ThingSpeak use with MATLAB, please select the Base64-encoded ASCII, single certificate option and save the .crt file.
Mozilla FireFox
1) Visit the api.thingspeak.com website, and click the padlock icon on the left of the address bar. Click Connection secure > More information:
2) Click View Certificate:
3) Select the DigiCert Global Root CA tab, and scroll down to the Miscellaneous section. Then, click the PEM (cert) link next to "Download" to save the certificate in .pem format to your computer.
Microsoft Edge
1) Visit the api.thingspeak.com website, and click the padlock icon on the left of the address bar. Click Connection is secure:
2) Click on the certificate icon.
3) Click the Details tab, make sure the DigiCert Global Root CA is highlighted as shown below, then click Export.
4) Save the certificate to your computer. You will have the option to save the certificate under multiple file types:
For ThingSpeak use with MATLAB, please select the Base64-encoded ASCII, single certificate option and save the .crt file.
You can also select a web site from the following list
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