What kind of feature are you missing? Where do you notice a shortcoming of PTB?

Next bot api update \o/

Describe the solution you'd like

Integration with Business Accounts [Taken by @harshil21]

• Added the class BusinessConnection and updates about the connection or disconnection of the bot to a business account, represented by the field business_connection in the class Update.
• Added updates about new messages in a business account connected to the bot, represented by the field business_message in the class Update.
• Added updates about message edits in a business account connected to the bot, represented by the field edited_business_message in the class Update.
• Added updates about message deletion in a business account connected to the bot, represented by the class BusinessMessagesDeleted and the field deleted_business_messages in the class Update.
• Added the method getBusinessConnection.

Working on Behalf of Business Accounts [Taken by @harshil21]

• Added the parameter business_connection_id to the methods sendMessage, sendPhoto, sendVideo, sendAnimation, sendAudio, sendDocument, sendSticker, sendVideoNote, sendVoice, sendLocation, sendVenue, sendContact, sendPoll, sendDice, sendGame, and sendMediaGroup.
• Added the parameter business_connection_id to the method sendChatAction.
• Added the field business_connection_id to the class Message.
• Added the field sender_business_bot to the class Message.

Information about Business Accounts [Taken by @aelkheir - #4183]

• Added the class BusinessIntro and the field business_intro to the class Chat.
• Added the class BusinessLocation and the field business_location to the class Chat.
• Added the classes BusinessOpeningHours and BusinessOpeningHoursInterval and the field business_opening_hours to the class Chat.

Mixed-Format Sticker Packs [Taken by @harshil21]

• Removed the fields is_animated and is_video from the class StickerSet.
• Added the field format to the class InputSticker.
• Removed the parameter sticker_format from the method createNewStickerSet.
• Added the parameter format to the method setStickerSetThumbnail.
• Increased the maximum number of stickers in any regular and mask sticker set to 120.
• Allowed to upload WEBM stickers using SendSticker.

Request Chat Improvements [Taken by @clot27]

• Added the fields request_name, request_username, and request_photo to the class KeyboardButtonRequestUsers.
• Added the fields request_title, request_username, and request_photo to the class KeyboardButtonRequestChat.
• Added the class SharedUser and replaced the field user_ids in the class UsersShared with the field users.
• Added the fields title, username, and photo to the class ChatShared.

Other Changes

• Added the field is_from_offline to the class Message. [Taken by @mahdyar - feat: add the field is_from_offline to the class Message #4189]
• Added the field can_connect_to_business to the class User [Taken by @harshil21].
• Added the field personal_chat to the class Chat [Taken by @harshil21].
• Added the method replaceStickerInSet [Taken by @harshil21],
• Added the class Birthdate and the field birthdate to the class Chat [Taken by @harshil21].
• Added the field BiometricManager to the class WebApp.

Describe alternatives you've considered

If you want to contribute, you can start from the Contribution Guide.

Additional context

Please comment below before start working on any part of the update so as to keep things in track and avoid double work.