Hi @Fernanda, Welcome to the Oracle Analytics Community!, and for posting your question.
@Aman Jain-Oracle - Thanks for the answer! To add, legend title/label customization is not currently supported on overlay chart (Oracle is aware of the requirement), but is for other viz types. If using an overlay chart, potential workarounds could be:
Hi @Fernanda, The legend title can be changed from the visualization Properties → General → Legend Title as shown in the screenshot below:
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