SuNāgarī Keyboard Layout with the regular as well as shifted keys is shown here.
The 'hal' key with red background will make half-forms of 'Nāgarī' consonants.
So to type 'प्य' first type 'प' then type '्' (hal, the red key) and then 'य'.
You may want to learn more on 'Typing Nāgarī Character Sequences'.
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