Segment information - Schedule of Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Segment Reporting Information [Line Items]
Total revenue	$ 36,074	$ 30,948	$ 70,972	$ 58,445
Segment Adjusted EBITDA	11,085	12,049	22,552	22,469
Subscription revenue
Segment Reporting Information [Line Items]
Total revenue	30,885	27,623	61,975	53,498
Hardware and other revenue
Segment Reporting Information [Line Items]
Total revenue	5,189	3,325	8,997	4,947
Total Regional Sales Offices
Segment Reporting Information [Line Items]
Total revenue	36,038	30,931	70,922	58,413
Segment Adjusted EBITDA	13,542	13,723	27,596	26,006
Total Regional Sales Offices | Subscription revenue
Segment Reporting Information [Line Items]
Total revenue	30,871	27,606	61,947	53,466
Total Regional Sales Offices | Hardware and other revenue
Segment Reporting Information [Line Items]
Total revenue	5,167	3,325	8,975	4,947
Africa
Segment Reporting Information [Line Items]
Total revenue	20,282	16,490	40,208	31,014
Segment Adjusted EBITDA	8,874	7,249	17,778	14,494
Africa | Subscription revenue
Segment Reporting Information [Line Items]
Total revenue	18,686	14,855	37,397	28,778
Africa | Hardware and other revenue
Segment Reporting Information [Line Items]
Total revenue	1,596	1,635	2,811	2,236
Europe
Segment Reporting Information [Line Items]
Total revenue	4,750	3,393	9,384	6,377
Segment Adjusted EBITDA	1,682	1,536	3,433	2,838
Europe | Subscription revenue
Segment Reporting Information [Line Items]
Total revenue	3,413	2,919	6,786	5,769
Europe | Hardware and other revenue
Segment Reporting Information [Line Items]
Total revenue	1,337	474	2,598	608
Americas
Segment Reporting Information [Line Items]
Total revenue	3,912	5,026	7,730	9,356
Segment Adjusted EBITDA	33	2,170	572	3,578
Americas | Subscription revenue
Segment Reporting Information [Line Items]
Total revenue	3,444	4,786	7,067	8,961
Americas | Hardware and other revenue
Segment Reporting Information [Line Items]
Total revenue	468	240	663	395
Middle East and Australasia
Segment Reporting Information [Line Items]
Total revenue	5,957	5,066	11,411	9,656
Segment Adjusted EBITDA	2,665	2,405	5,208	4,323
Middle East and Australasia | Subscription revenue
Segment Reporting Information [Line Items]
Total revenue	4,207	4,118	8,556	7,999
Middle East and Australasia | Hardware and other revenue
Segment Reporting Information [Line Items]
Total revenue	1,750	948	2,855	1,657
Brazil
Segment Reporting Information [Line Items]
Total revenue	1,137	956	2,189	2,010
Segment Adjusted EBITDA	288	363	605	773
Brazil | Subscription revenue
Segment Reporting Information [Line Items]
Total revenue	1,121	928	2,141	1,959
Brazil | Hardware and other revenue
Segment Reporting Information [Line Items]
Total revenue	16	28	48	51
Central Services Organization
Segment Reporting Information [Line Items]
Total revenue	36	17	50	32
Segment Adjusted EBITDA	(2,457)	(1,674)	(5,044)	(3,537)
Central Services Organization | Subscription revenue
Segment Reporting Information [Line Items]
Total revenue	14	17	28	32
Central Services Organization | Hardware and other revenue
Segment Reporting Information [Line Items]
Total revenue	$ 22	$ 0	$ 22	$ 0