If it is not you could change the strict to output in GB (or what ever value you choose, check man page for DF), you could change the script to output the results of df --block-size=GB . If modifying the script is not possible you could try the following command
*| multikv fields Filesystem Size Used Avail Use% | eval Used=if(match(Used,"\d+G"),rtrim(Used, "G"),Used) |eval Used=if(match(Used,"\d+K"),rtrim(Used, "K"),Used)| eval Used=if(match(Used,"\d+M"),rtrim(Used, "M"),Used)| table Used
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