TemplateToaster provides option to draw widget areas within header in your template, to draw widget please follow the steps provided below -
Go to TemplateToaster -> Widget areas tab -> Draw position -> Widget areas -> header -> blank area named "HeaderPos1" will be there within header ( you may also change the name of the widget area by clicking on edit icon).
Please refer to point 16 under - https://kb.templatetoaster.com/widget-areas-module-position-regions-block-reference-tab-templatetoaster/
Now, after installing theme to WordPress end,
Go to WordPress dashboard -> Appearance -> widgets-> place your required widget with above drawn widget area.