If we want to use numbers, there can not be a symbol. If there is a point for decimals it won´t take it as numbers. So remove the symbol and change the point for a colon.
https://wpdatatables.com/documentation/creating-new-wpdatatables-with-table-constructor/importing-data-to-editable-mysql-table-from-excel-or-csv-with-table-constructor/ What if there is a formula in the google sheet?
You can take a look on this link how to make button with class. Then insert that code in in Custom wpDataTables CSS under the "Custom JS AND CSS" in main settings of wpdatatables. And then insert that class name without dot in field Button class on DATA tab in column settings for that URL column.
You can use this CSS code to set the width for the images
Go to settings, and custom jss css and in the css part input this.