Bank loans (Details) - USD ($) |
Mar. 31, 2022 |
Mar. 31, 2021 |
|---|---|---|
| Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] | ||
| Bank loans | $ 828,682 | $ 663,505 |
| China Construction Bank 1 [Member] | ||
| Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] | ||
| Bank loans | 257,997 | 402,254 |
| Beijing Wholly Bank 1 [Member] | ||
| Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] | ||
| Bank loans | 204,032 | 0 |
| Beijing Wholly Bank [Member] | ||
| Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] | ||
| Bank loans | 462,029 | 402,254 |
| China Construction Bank [Member] | ||
| Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] | ||
| Bank loans | $ 366,653 | $ 261,251 |