Unable to upload csv file to my channel

Im not able to upload a csv file which I have created using rpi. The csv file is as follows

datetime field1 field2 field3 2021-04-19-10:59:46 0 0 0 2021-04-19-10:59:47 122 -1 265 2021-04-19-10:59:48 123 -1 265 2021-04-19-10:59:49 115 0 266 2021-04-19-10:59:50 122 -7 265 2021-04-19-10:59:51 117 -5 265 the error I get is invalid csv file or contains duplicate timestamp or missing timestamps. If someone could point out the mistake, it would be helpful.