You need to use the big data masking tool: Mask. The specific steps are:

Find those two points that don't conform to the linear pattern in the data table, select them, and then click the right mouse button, choose Mask --> Apply;

Then, you will see the data table In the data table and in the graph, the two points that don't fit the linear pattern have turned red, which means that these two points have been masked;

Then you can fit the remaining data points linearly, and the fitting steps are the same as the regular linear fitting, so I won't talk about it here;

After the end of the fitting, you need to go back to the original data table again, select the two data points that have been masked just now, and then click on the right button of the mouse and select Mask --> Apply. right-click and select Mask --> remove. This will restore the masked data points and change the color back to black.