Try SAS analysis. No hindrance at all, you will get what you want.....

This is 'Duncan grouping' in SAS

https://support.sas.com/documentation/cdl/en/statug/63347/HTML/default/viewer.htm#statug_anova_sect027.htm

In attachment the SAS program. Nowadays SAS uses coloured bars.

SAS can be run online:

https://www.sas.com/en_us/software/on-demand-for-academics.html

I recommend that you can use SPSS to calculate the differences, like T-test, variance analysis, kappa-test.

Thank you very much for your help

You Can also use LSD test in Statistica or minitab software