showing chart based on Time and Transaction count

[avikc100]

this is the log data

i want a report like this:

my current query is :
index="webmethods_prd" source="/apps/WebMethods/IntegrationServer/instances/default/logs/DFO.log" |eval timestamp=strftime(_time, "%F") | stats values(B2BUnknownTrxCount) by timestamp

it giving report like this:

I need to add date time in hh:mm in a chart. 
Please help to update my query

[avikc100]

index="webmethods_prd" source="/apps/WebMethods/IntegrationServer/instances/default/logs/DFO.log" |eval timestamp=strftime(_time, "%Y-%m-%d %H:00") | stats values(B2BUnknownTrxCount) by timestamp

[macalamela · Accepted solution]

index="webmethods_prd" source="/apps/WebMethods/IntegrationServer/instances/default/logs/DFO.log"
| eval timestamp=strftime(_time, "%F"),hour=strftime(_time, "%H,%M") 
| stats list(hour) as hour, list(B2BUnknownTrxCount) by timestamp