NPM DB Index Fragmentation

I've just implemented AppInsight on both of our NPM SQL DB's, one DB is fine but the other one is showing 10 indexes over 75% fragmentation of which 5 are over 83% and ones 0ver 90%.

I thought Indexes were fragmented as part of the overnight NPM maintenance, if this isn't the case how do I go about fragmenting the indexes (I have little SQL knowledge and we don;t have a DBA)?

Thanks

Jon