input gst against interstate delivery

As per section IGST Act 10(1)(b)

Goods are delivered by the supplier to a recipient or any other person, on the direction of a third person by way of by way of documents of title to the goods or otherwise

Hence you can send goods as per following

Bill to : To your dealer , charge CGST/SGST
Shil to : Address where goods to deliver

Yes , your dealer can claim ITC

please say whether the following statement is true or false "There is no procedure available in the GST Law to bill to one address
in a state and deliver to another address in another state under the
same invoice"

As per section IGST Act 10(1)(b)

Goods are delivered by the supplier to a recipient or any other person, on the direction of a third person by way of by way of documents of title to the goods or otherwise

Hence you can send goods as per following

Bill to : To your dealer , charge CGST/SGST
Shil to : Address where goods to deliver

Yes , your dealer can claim ITC

The facility for billing to one address of the registered person and
delivery to his another address is available only within the state
under one GST registration that also if such address is listed in his
additional place of business.  This facility is not available
interstate.

Have refer the Eway Portal , there is various modules for generations of Eway Bills, ie
Bill To , Ship To , despatch from ,.. all are being used in the query raised by You & Kindly also refer the above section mention by me

Whether transfer of goods to another branch located outside the State is taxable?
Ans. In terms of Section 25(4) of the CGST Act, 2017, every person who is required to obtain
separate registration for every branch located in different State or Union territory shall
be treated as distinct persons. Accordingly, the supply of goods (stock transfers) to a
branch located outside the State would qualify as supply, liable to tax in terms of
clause 2 to Schedule I of the CGST Act, 2017. Further, it is important to note that,
supply of goods to a branch/ unit located within the same State having separate
registration would also be liable to tax since both such units (supplying unit and
recipient unit) would qualify as distinct person in terms of Section 25(4).