Add a column in templates with tax for individual items

How to add a column in templates with tax for individual items and that must be calculated in total.

You do not. And you do not need to in your jurisdiction. The requirements of your tax law are that the tax rate must be shown, which Manager does, not the tax amount. Manager’s standard invoice meets your legal needs. The total tax amount for the invoice is shown in the totals section for every tax code used on an invoice.

Following are the mandatory requirements for Saudi Arabia.
The templates are having only english. Is there any formats available suitable for saudi arabia?
Link:Item 2.2… https://www.vat.gov.sa/en/introduction-to-vat-teh/faq/technical-faqs

The VAT Invoice must include the following details in Arabic, in addition to any other language also shown on the Tax Invoice as a translation:
a) The date of issue;
b) A sequential number which uniquely identifies the invoice;
c) The Tax Identification Number of the Supplier;
d) In cases where the Customer is required to self-account for Tax on the Supply, the customer’s Tax Identification Number and a statement that the Customer must account for the Tax;
e) The legal name and the address of the Supplier and of the Customer;
f) The quantity and nature of the Goods supplied or the extent and nature of the Services rendered;
g) The date on which the supply took place, where this differs from the date of issue of the invoice;
h) The taxable amount per rate or exemption, the unit price exclusive of VAT and any discounts or rebates if they are not included in the unit prices;
i) The rate of Tax applied;
j) The Tax amount payable, shown in riyals;
k) In the case where Tax is not charged at the basic rate, a narration explaining the Tax treatment applied to the Supply;
l) In cases where the margin scheme for used Goods is applied, reference to the fact that VAT is charged on the margin on those Goods.

Yes, but this doesn’t have to be per item unless the invoice contains different tax rates.
When all invoiced items are at the same tax rate, then only the tax rate and tax amount payable for the entire invoice needs to be shown, which Manager already does in the total section.

If you search the forum for UAE, a very similar discussion has occurred there.

Select your language under Preferences.

As for your other items, using your letter designations:

a) Automatically included on all transaction forms
b) Automatica except for bank transactions, where you enter the bank’s transaction number
c) Put this in Business Details under Settings
d) Use custom fields for both. The customer’s ID field should be created under the customer and the note on self-accounting added to the invoice.
e) Define your own under Business Details and the Customer’s in the Customers tab.
f) Enter by line item when creating the invoice
g) Use a custom field if necessary
h) Automatic for each tax code used
i) Enter by line item
j) Shown automatically (set your base currency as riyals)
k) Enter in a custom field, such as Notes
l) Same

No custom theme is necessary. All of this will work on any built-in theme selected.