To update your product rates you must access Settings > Import/Export > Export to file , in Type of information select Products, in Excel format, switch from available attributes to selected attributes the information you want to get from it, ex. Product Reference, Name, Base Price and Rates, finally click on Export.
.Once you have your prices updated in the Excel file, you must access Settings > Import/Export > Update from file.
.You have to indicate in Type of information "Products", key attribute "Reference", you have to take into account that if the references of our products are Manual, you have to indicate it in the field Reference > Manual. Define the rest of the attributes, if new items are going to be added in this list we have to mark that they are created, otherwise just indicate "update existing items".
Finally add the file by clicking on Select a file, rename each column and click on Update. When performing an update you can upload files with a maximum of 1,000 lines, therefore, if you have a file with more lines you must split the Excel files.